Cognitive impairment at age 5 years in very preterm infants born following premature rupture of membranes.

OBJECTIVE: To evaluate the relationship between preterm premature rupture of membranes (PPROM) and cognitive impairment in 5-year-old children born very preterm. STUDY DESIGN: The Etude Epidémiologique sur les Petits Ages Gestationnels Study is a population-based cohort of children followed up from birth to age 5 years recruited in 9 French regions in 1997. We analyzed data from singletons born between 24 and 32 weeks gestation categorized into 4 groups according to etiology of prematurity: infants born after PPROM, after idiopathic preterm labor, in a vascular context (Vasc), and to women with other complications (Other). Cognitive development at age 5 years was assessed using the Mental Processing Composite score of the Kaufman-Assessment Battery for Children. RESULTS: Among the 1051 children followed up to age 5 years, the mean Mental Processing Composite score was 93.6 ± 19.7, and 13.3% of the children (140 of 1051) had cognitive impairment. After adjustment for potential confounders, the risk of cognitive impairment among infants in the PPROM group was not significantly different than that in the idiopathic preterm labor group (OR, 1.09; 95% CI, 0.62-1.92) and the Other group (OR, 1.36; 95% CI, 0.75-2.47), but was lower than that in the Vasc group (OR, 1.86; 95% CI, 1.16-2.97). In the PPROM group, the risk of cognitive impairment was greater when the latency period (ie, time from rupture to delivery) was <3 days (OR, 2.32; 95% CI, 1.07-5.02). CONCLUSION: Preterm infants born after PPROM are not at increased risk for cognitive impairment in childhood, but the time between PPROM and birth may influence that risk.

Hyperventilation during exercise in very low birth weight school-age children may implicate inspiratory muscle weakness.

OBJECTIVES: To study the ventilatory response during exercise in 8- to 10-year-old children born in 1998 to 2000 with a birthweight <1500 g (very low birthweight [VLBW]). STUDY DESIGN: We studied 19 VLBW children and 20 full-term children paired for age and sex. A physical activity questionnaire was administered. Lean body mass, spirometry, and maximal inspiratory pressure were assessed at rest. Gas exchange, breathing pattern, and the tension-time index of the inspiratory muscles, a noninvasive indicator of inspiratory muscle effort, were evaluated during a continuous incremental cycling protocol. RESULTS: VLBW children had lower weight, height, lean body mass, and maximal inspiratory pressure than control subjects. Their physical activity level was not different. During exercise, they had a higher respiratory rate and minute ventilation for the same metabolic level (VCO(2)/kg) and a higher tension-time index of the inspiratory muscles for the same exercise level (percentage of maximal oxygen consumption). CONCLUSIONS: The lower inspiratory muscle strength observed in school-age VLBW children resulted in a higher inspiratory effort during incremental exercise. The rapid but not shallow breathing pattern adopted by this population during exercise may have been in response to their lower inspiratory muscle resistance to fatigue. VLBW children complaining of dyspnea should be investigated with exercise testing.